JohnMo

Two rows of panels between the roof windows, fully integrated no need to slate in those areas. We didn't do external blinds just internal, with roof overhangs for summer shading.

Roof slates and integrated PV. We have UFH in bedrooms but I am not sure it's a good choice, if you are having fan coils any way, not not use then for heat and cooling. Reason I think not a good choice, the floor takes an age to heat up and cool back down again. So you go to bed in a warm or hot room that stays like that the rest of the night. Radiators or fan coils quick to heat and the heat doesn't hang about that long after. The A2A should do heating also. Yes lots of glazing and well insulated warm house. 16 to 17 for the last few days, the odd bit of sun, house hasn't dropped below 22 even with doors and windows open. Internal or external blinds are a must have.

Million pound build and concrete roof tiles, really? Hope you getting a huge array for the cost of the PV. Otherwise you are wasting money. You seem to be double dipping with a heat pump for heating and another for cooling, could they not be combined. A heat pump that does cooling and the ufh heating then engage a single system to cool or heat? You are having UFH which is out of sight, then adding fan coils which are in your face to look at and to blow air at you.

We have only got 52 tonnes of floor slab to play with. Stuffing heat into works well. We put 30 degree flow temp in it for about 5 to 6 hours, that's enough to last 18 hours, until the next charge.

OSO, do A rated cylinders, heat loss about 0.8kWh per 24 HR.

And no electronics to fail, or generally no reliability issues.

If your really lucky it will be a heat pump dryer.

Can't you do that with a normal cylinder, why do you need a sunamp? Just get a A rated cylinder for a 1/3 the cost.

Basically the exact same route on our build, only difference is we have a dry ridge (mortar bed isn't allowed on new builds in Scotland) and we have sarking boards (another Scottish thing) below the breather membrane.

Is this a new build or existing, as I thought you had to install a treatment plant now. Which has a separate soakaway. Can't get pea gravel, crushed stone or what ever your install manual says. Get from builders merchants or direct from a quarry for half the cost.

Not sure of the original energy rating. But it leaked heat quite well. I had a section of the additional insulation off yesterday and you could feel outside of the cylinder hot. Which you didn't before. It still looses heat quicker than I want.

May be worth reading the specification. Look at the intermittent and long term max temperatures. Our circulation pump lets us set times and temperature of the hot water circulation, we only have it on for an hour or so morning and evening at around 40 degrees. So would see any issue with any pipe material suitable for domestic plumbing.

I made one for mine, used off some vapour control fabric/foil, some left over mineral wool and double sided tape. Made a load of pillow/cushions, shaped to go around the cylinder. Two layers of vapour control fabric (back to back), double sided tape on 3 sides, fill with mineral wool seal with double sided tape. They can be easily removed if I needed access. Heat exchanger is wrapped in 25mm PIR. Took about an hour.

Think it makes good sense in the summer when it's hot, as you can use to cool the slab. But at almost any other time, you are taking heat out of the floor provided by another source, i.e. a boiler, heat pump, even solar gain etc. So if you take a kW away out of the UFH return flow you need to add kW at the other end to keep things in balance. So would it be more cost effective just heat DHW from the normal source of heat.

https://www.partel.co.uk/product/21/5/alma-vert-115-kgm Slightly different product but in sheets

Last month and this month so far, my gas bill has consisted of 1/3 actual gas usage and 2/3 for the standing charge. It wasn't that long ago that Ofgem or similar, said all energy companies had to apply a standing charges. I used to use Ebico, purely because they didn't apply a standing charge.

Building Regs applicable to the area of the UK you live, should all the info you need.

They already tax you for buying a second home in Scotland, at time of purchase. I thought they only wanted to stop new homes being build, if they could be purchased by anyone, but them, at a reduced price?

If you really want to kill everything that may be in chlorinated water, then 60 degC is enough, you don't need it at 70 degC. Bet the thermostat is set at 70 degC or very close to it. That is why the boiler is never switching off

But doesn't the thermostat need connecting in to the boiler control circuit, to do anything. The middle grey box, which I assume is the thermostat for the cylinder is not connected to anything as there are no wires coming out of it.

If you just want to heat the towel rails from you central heating, you will end up with the boiler short cycling if they are the only thing asking for heat. Have you thought about making them dual fuel, by adding electric elements? Then you can add a simple time switch to heat the rail when you out wet towels on it.

Does your cylinder have a thermostat? You need the thermostat to call for heat and shut off heat based on your time schedule. So the wiring goes from the thermostat via the time switch or your smart hub to the boiler. So your smart hub isn't really that smart!

You beat me to it

So your usage is down to 3.2kWh per day, from 18kWh per day. That sounds like a win. £1600 saved in water heating costs!

You can if you have cylinder upstream of the combi. Just set up to do some experimenting, as we have quite a few days of overcast skies coming up/ Already have a buffer (thermal store) on the heating system, which has a DHW coil in it, this is used to preheat water going in to a combi in the heating season and heated by PV immersion in the summer. Downstream of the DHW coil is solar diverter valve (to a mixer valve or to combi). On a good solar we have free hot water. Have a good idea of gas used for DHW, when there is little or no solar. Have just set the heating system to charge the buffer at 47 degrees, 4 degrees hotter than the diverter is set at. Will see how gas consumption goes, over the next week or so. Have already noticed the draw of volume at the kitchen sink, is much lower with the heated buffer, than with the combi.